Improvement in differential pulley-blocks



ZVSheetS--Shet i- GEORGE F. CLEMONS & MELVILLE CLEMENS.

improvement in Differential Pulley-Blocks.

Patented April 23, i872.

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A y 2SheetsV-Y-Sheet`j2. GEORGE F; CLEMONS 8L M ELVILLE CLEMENS;y

Improvement in Differential Pulley-Blocks. No, 125,882, PatentedApriv|23,1872.

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Iwzzmm GEORGE F. OLEMONS, OF SPRINGFIELD, AND MELVILLE CLEMENS, OF

I BOSTON, MASSACHUSETTS.

IMPROVEMENT I DIFFERENTIAL PULLEVBLOCKSIl Specification forming part ofLetters Patent No. 125,882, dated April 23, 1872 antedated April 6,1872.

Specification describing certain Improvements in Dii'erentialPulley-Blocks, invented jointly by GEORGE F. GLEMoNs and MEL- vLLEGLEMENs, residents, respectively, of Springield, in thev county ofHampden and State of Massachusetts, and of Boston, inthe county ofSuii'olk and State of Massachusetts.

Our said invention relates to the adaptation of differential-groovedpulley-blocks in hoisting-machines, and its characteristic features areas follows, viz.: First, combi ning, with differential-.grooved pulleys,pressure-rollers which are adapted to press and clamp the hoisting-ropeor chain in the grooves of the pulleys to make the rope or chain bindtightly in the grooves without slipping when a weight is suspended byit. Second, employing, in combination with differential-grooved pulleysand rope-tightening pressure-rollers, supplementary ditierential-groovedpulleys or rollers, placed below and in the vertical planes of theprimary pulleys, for the purpose of giving additional security againstthe slipping` of the rope or chain. Third, combining` thedifierential-grooved pulleys andfchain-tightening pressure-rollers withthe commonly-used differential-horned pulley-blocks, for the purposes ofpreventing the rapid wearing of the chain and the pulley-horns, and toobviate the noi-se and jar and the danger resulting from the slipping ofthe chain on the horns in hoisting heavy weights. Fourth, covering thegrooves of the differentialgrooved pulleys with leather or othersuitable material for giving them durable and frictional surfaces forthe hoisting-rope or chain to run on.

Figure l is a side elevation, showing the hoisting-machine with primarydifferentialgrooved pulleys combined with rope-tighteningpressure-rollers and supplementary differential-grooved pulleys. Fig. 2is an elevation, showing that face of the machine which is at the lefthand in Fig. 1, with the hoisting-ropes broken away below thesupplementary pulleys. Fig. 3 is a side elevation similar to Fig. l,

showing the primary differential-grooved pulv leys and chain-tighteningpressure-rollers, in combination with common differential chainhornedpulleys substituted for the supplementthe primary pulleys, made of wood,and their grooves covered with leather. Fig. 5 is a transverse centersection of the primary pulleys, made of cast-iron, and their groovescovered with leather. Figs. 6 and 7 show, by a side elevation and acenter section, a mode ot' adaptingthe suspended weight to act to clampthe rope between the differential pulleys and pressure-rollers. Figs. 8and 9 show in like manner the same, with double-grooved di'erentialpulleys and double rollers, adapted to y give adjustable clamping uponthe rope between them. Figs. l() and l1 show, by enlarged scale, thedevice for making the said clamping action adjustable.

The pulley-blocks are supported in a frame, consisting of a yoke-piece,a, with a suspending hook, b, swiveled in it, and parallel sidestraps cc with vcross-bars d d attached to it, and connected by four axle-pins,e, f, g, and h. Upon the axle-pin e revolve' two grooved pulleys,i andj, united together in one pulleyblock, and of different diameters ofthepitch circle of their grooves as eleven is to twelve. Upon the axle-pinf revolve two supplementary differential-grooved pulleys, 7c and Z,united in one pulley-block, and having their grooves of the samerelative diameters as are the grooves ofthe primary pulleys i and j, andplaced, re-V spectively, in the same vertical planes. Upon the axle-pinsg and h revolve two pressure-rollers, m and a, which are covered withrubber bands. The roller m is placed in the plane of the groove of thepulley 1'., so as to press upon and clamp the rope in its groove, andthe roller n is placed so as to press similarly upon and clamp the ropein the groove of the pulley j. o is a grooved tackle-block pulley,carried in a guard-frame,p,which has a tacklinghook, q, swiveled in itsbottom. An endless rope, tting the grooves in the pulleys, passes in twofolds over the primary pulleys t' and j, and in one fold under thetackle-block pulley o, the same as in common differential pulleyblockhoisting-machines; but in passing it also over the supplementary pulleys7c and l, as shown, the weight ends of the rope are gathered together,crossed, and lapped upon the primary pulleys. The supplementary pulleysk and Z serve to co-operate with the primary pulleys t and j insupporting a weight suspended on the tackling-hook q, and they alsoincrease the effective operation of the primary 2 leases pulleys bytheir lapping the rope upon them. The pulleys k and Z may be madeseparate, to lact as independent rollers, and only to gather and lap therope upon the primary pulleys; or they may be dispensed with for raisinglight weights. The rollers m and n serve to press and clamp the ropefirmly in the grooves of the pulleys, at the lead-on and lead-oi' pointsof the loose fold of the rope, so that when a weight is suspended on thetacklinghook q it stretches the rope tightly in the grooves, wedging itbetween their sides, and it is held thereby from slipping in thegrooves. A weight attached to the hook q acts to revolve in oppositedirections, both the lower and the upper pulley-blocks k l and 'L' jwith rotary forces, differing in the proportion of the relativediameters of their grooves, or as eleven is to twelve. And the greaterrotary force being insufficient to overcome the less rotary force, andalso the friction of the moving parts of the machine, the weight willhang suspended, free to be raised or lowered by pulling down either uponthe part t or the part u of the rope.

. Fig. 3 shows common differential horned pulley-blocks v and w,substituted in the described combination for the pulleys k and l, and achain, fitting the horns of the pulleys, in substitution for the rope.The pulley t has eleven horns andthe pulley w has twelvehorns, so thatthey take up and let oif the chain in unison with the correspondingmovements of the grooved pulleys. The grooved pulleys relieve and steadythe load upon the horned pulleys, preventing the rapid wearing away ofthe pulley horns and the wear and stretching of the chain, commonlyresult-ing by holding it from slipping as its links are successivelyengaged by the horns, thus obviating the rattling and jarring, anddanger of breaking of the chain in its common use.

Fig. et is a transverse center section of the pulleys, showing a mode ofmaking them of wood and covering them with leather. The pulleys areiitted upon cast-iron. hubs w w, which have flanges y y fastenedtogether and clamped upon the sides of the pulleys by screw-bolts z z.Upon the peripheries of the pulleys are formed like grooves, which arecovered with leather bands a and b', fastened to the pulleys by pegs c cand glue or cement.

Fig. 5 is a transverse center section, showing the pulleys cast inseparate pulleys d and e', and fastened together by having thecontiguous sides of their hubs and flanges clutchjointed, and boltedtogether by screw-bolts f f. The pulley rims are made with like grooves,which are covered with leather bands g and 7L', fastened to the rimswith copper rivets.

Rubber or other suitably durable and frictional material may be used inthe grooves of the pulleys 'i and j or 7c and l, but for light work orin using a ibrous rope it is not required, and they may be made, likecommon grooved pulleys, of iron or wood, with the sides of the groovessuitably inclined or curved to fit and hold the rope. The rollers mand nmay be made and supported like common pressure-rollers, leather-covered,or of wood or metal surfaces, grooved or plain, and supported inadjustable spring-pressure or weighted boxes to clamp the rope in thepulleygrooves. A convenient way to make their pressure adjustable is tomake their axle-pins to turn eccentrically in their end bearings, withsuitable attachments to revolve and secure them in position, therebyenabling throwing the rollers in and out from the pulleys and adjustingtheir clamping pressure. Springplates, with or without adjustablepressure attachments, may be used in place ofthe rollers to press andclamp the rope into the pulley-grooves, but with less advantages ofoperation than the rollers. The weight suspended upon the tackling-hookq may be made to give the required clamping-pressure of the rollers mand n. Such a mode of operating the pressure-rollers is shown in Fig. lby dotted lines, and also in the accompanying model.

In Fig. 1, z" z" and j j are straps or rods connecting the ends of theaXle-piuf, respectively, to the ends of the axle-pins y and h of therollers. The bearings of the axle-pins g and h in the cross-bars d d areslotted, so that the rollers m and n may be moved in and out from thepulleys; and the end-bearings of the axlepin fare slotted vertically, sothat the axlepin may be moved up and down. By these means the verticalforce of the weight being hoistedis taken upon the axle-pins g and h,and acts partly to draw the rollers m and n toward each other and topress them against the rope, with clamping forces varying as the weightsare increased or decreased.

ln the model one end of each axle-pin of the rollers is stationary, andtheir other ends operated horizontally, as described, by but two strapsattached to opposite ends ot' the axlepin f. This modification may beused, or another modication, which is to make the ends of the rollersaxle-pins and the axle-pin f all stationary on one side of the frame,and to slot, as described, their end-bearings in the frame on the otherside, and connect the latter-named ends by the straps i and j.

The weights hoisted may be made to clamp the rope or chain, as required,between the pulleys c' and j and rollers placed below them, as is shownin Figs. 6 and 7, on Sheet No. 2 of the drawing.

Upon the axle-pin f are iitted, to revolve independently, two groovedrollers, r and sf, of suitable diameters to clamp equally the ropes inthe two grooves of the pulleys c' and j; and the ends of the axle-pin eare feathered on two sides and fitted to slide freely up and down invertical slots q q in the frame, so that a weight on the hook q willpull down on the pulleys z' and j and clamp the ropes in their groovesand in the grooves of the 'rollers r and s at the lead-on and lead-offpoints of the loose or hoisting fold of the rope.

To prevent crushing of the rope overmuch,

massa t 3 the han ges of the grooves bot-h of the pulleys and rollersmay be adapted to meet and roll upon each other when the rope issufficiently compressed and clamped in the grooves to hold it fromslipping; or, the axle-pin c may be adapted to touch and rest in thebottom of v the slots q g', when the rope is suiiiciently "which theweight-told of the rope may hang,

if desired, instead of being carried over the pulleys z' and j, asshown.

The clamping pressure produced by the weights may be made adjustable, asshown in Figs. S and 9, and by enlarged scale in Figs. l0 and ll, bycarrying the iiattened ends ot' the axle-pin e in slotted circularplates o o', which are adapted to revolve on projection of them, x x',in holes in the frame, and which are adjusted and secured to the ame byscrewbolts y y', passing through curved slots in the plates. Theinclined slotted bearings w w' of the axle-pin c support partly theweight suspended upon the hook q, and by adjusting the pla-tes o c tobring the slots more or less inclined the weight is proportionablythrown upon or taken oil' from the rollers i" and s.

The described mode of causing a rope or chain to be held and to bindtightly in grooved pulleys, by means of rollers or spring-plates, whichare adapted to press and clamp it in the pulley-grooves at the lead-onand lead-off points of the loose fold of the rope or chain, isapplicable for other grooved pulleys or wheels than those used inpulley-blocks and tackle; and grooved pulleys used for transmittingpower with iibrous or wire ropes may be made greatly more efficient anddurablev by using the described means of pressing and clamping the ropesinto the pulley or wheel grooves at the lead-on and lead-off points ofthe loose half of the ropes. In this way the ropes are held positivelyfrom slipping, which 1` prevents the rapid wearing of the grooves, andthe power is transmitted independently of the length orweight of theropes, and the ropes may be used to transmit power efticiently at shortdistances.

We claim as our inventionl. The ropeV or chain tighteningpressurerollers g and h, and their described moditications, employedsubstantially as set forth.

2. The differentialgrooved pulleys iandj, combined with thepressure-rollers g and h, substantially as and for the purposes setforth.

3. The supplementary pulleys lc and l, employed substantially as and forthe purposes set forth. 4

4. The differential horned pulleys o and w, combined with thedi`erentialgrooved pulleys i and j and pressure-rollers g and h,substantially as and for the purposes set forth.

5. The described mode of producing the pressure of the rollers g and h,according to the weight being hoisted, by means of the connecting-straps'i' and j', operating substantially as described, or by other equivalentpressure-producing connections of the weight to the rollers.

6. The clamping-rollers r and s', employed in combination with thegrooved pulleys i' and j, and adapted to operate together, substantiallyas and for the purposes set forth.

7. Regulating the weight-pressure upon the j rollers i" and s by meansof the adjustablyslotted axle-pin bearings o o of the pulleys z' and j,or by other equivalent weight-pressure, regulating connection oftheweight to the rollers.

GEO. F. GLEMONS. MELVILLE CLEMENS. Witnesses:

RICHARD WELCH, LAURA D. CLEMoNs.

